I didn't really see any organised tours in Kruger.
You can hire a car and drive in - it is well signposted and marked and there are good roads.
It is safe and you cannot drive at night.
If you book your car and accommodation (I can't recommend the "camps" highly enough!) you can't go wrong. There are good restaurants at each campsite along with small shops where you can by anything you might need (along with books and local made products). It is very very well organised and run. You can book morning or night tours at each camp which go for 3hrs (about) so you don't have to do all the driving (you can book these before you go, or book when you get there).
I think i stayed at Satara and Lower Sabie Camps - two nights in each, but I can't quite remember.
Your daughter will have an absolute fantastic time, as will you.
I am no expert on KNP, but I am happy to answer any questions you might have - just message me.